Process of treating petroleum residues.



C. S. PALMER.

PROCESS OF TREATING PETROLEUM RESIDUES.

APPLICATION FILED MAR. 2, I907- Pa'tented June 13, 1916.

LET/Q CHECK VALVE I mmmbwmmml m U M TEMPEHATURESI I 170 I I 200 2!!) 220 230 240 250 260 270 280 290 3 CHARLES S. PALMER, OF UPPER MONTCLAIR, NEW JERSEY.

PROCESS OF TREATING PETROLEUM RESIDUES.

- Specification of Letters Patent.

Patented June 13, rain;

Application filed March 2, 1907. Serial No. 360,975.

compounds from petroleum residues, such as Florence, Boulder, Wyoming, California and Louisiana residues or pitches which are substantially non-volatile below 300 Centigrade.

The usual process of cracking or decomposing petroleum residues consists in subjecting the same to a high degree of heat "whereby they are partially decomposed and disintegrated into volatile compounds. These are simultaneously distilled with the result that more or less residual coke or carbonaceous residue is produced. This carbon or carbonaceousresidue resulted from the decomposition of the compounds treated, into free carbon, at the relatively high temperature and relatively low pressure employed. In practically all cases where pressure was employed the temperature was in excess of 350 CL, whereas the pressure was at or below two atmospheres.

The important features of my process consist:

(1.) In the complete separation of the socalled cracking from the step of distilling, the former being carried out at high pressure, usually in excess of four atmospheres, while the latter is conducted preferably at or below atmospheric pressure.

(2.) In conducting the cracking in heavily constructed digesters capable of with standing enormous pressures, while supplying sufficient heat thereto to liquefy, to volatilize, to create a predetermined pressure, e. autogenous pressure, to furnish latent heat of volatilization, and to furnishthe requisite endothermic heat of formation.

(3.) In utilizing the pressure element to direct and control the reaction quite contrary to usual expectations, the greater the pressure the greater will be the decomposition, recomposition and polymerization into volatile products, which are formed in spite of the pressure and work with and intensify the pressure. The pressure is controlled in each case by the equilibrium established and varies according to the materials treated, the resulting products, and the factors of heat and time of action but ordinarily the pressure when it reaches 130 pounds is suflicient to effect the necessary conversion.

(4;.) The time of action. This usually, aside from the time required for the preliminary melting and heating in the reser: voir, occupies but a very few minutes.

In carrying out the said process in accordance with my invention, the residues, substantially nonvolatile below 300 (3., such as Florence, Boulder,Wyoming, California and Louisiana pitches or residues, are first introduced into a steam.

jacketed reservoir wherein the same are melted, and thence are introduced into a high pressure digester wherein they are subjected to the requisite conditions of temperature and pressure necessary for carrying out the process, the means for producing the requisite temperatures and pressures &c. being indicated in the drawings accompanying this specification and forming a part thereof.

In the drawings, Figure 1 is an elevation chiefly in section of an apparatus adapted for this purpose. Fig. 2 represents a curve illustrating the process in operation.

Referring to the; drawings the reference numeral 1, designates a tank or reservoir provided with a cover, 2, a steam-jacket 3, a drainage pipe 4, and a steam inlet pipe 5.

An outlet pipe 6, provided with a .valve 7, is

connected by a pipe 8, provided with a valve 9, with a digester 10. The digester, which is constructed preferably of half-inch steel,

' is provided with a cap or closure 11, securely packed in the-usual manner, a manhole 12, and pipe extensions 13, 14 and 21 respec tively. A jacket 15 preferably as shown being provided with steam coils 16, completely surrounds the said digester, openings being provided in both the digester and the said jacket for the insertion of a pressure-gage 17 and a thermometer 18. The pipe-extensions 14 and 21 project through the jacket 15 and are provided with a check'valve 19 and a stop-cock 20 respectively. These extensions are connected with piping 22 and 23 to a ,still 24, of well known construction, pro-' vided with the usual steam-coils 25, inlet .vapor outlet 27, and thermometer 28.

. The residues treated in the above described apparatus, as actually practised, consisted-in so far as could be determined from the specific gravity and melting points, of

mixtures of hydrocarbons of the paraffin se ries C H of the range O l-l to C H Said residues are empirically known as residues or pitches from, as for example Florence, Wyoming, California and Louis iana pitches, which were the ones actually tested and operated on by this process.

During the treatment in the digester, 10, which usually did not exceed. afew minutes, the pressures gradually increased with the temperature, according to the curve shown in Fig. 2, until a pressure of 130 pounds was reached, when there was apparently a sudden conversion of the materials present into more volatile compounds which caused a ra aid increase in the pressures as shownwithout the indication of any great increase in temperature. Since the heat was being uniformly applied thereto, it is apparent that at this pressure there was a large absorption of heat, which prevented any noticeable indication of an increase in temperature. Such absorption of heat being evidently due to the formation of newcompounds which as the results show are to a certain extent, at least, cyclic in character.

In order that thepressure maybe accurateiy controlled during the operation, I provide the check valve 19, which may be adjusted for any degree of pressure desired, whence upon .an increase of the pressure above that to which the valve is set, the vapors from the digester will pass over into the still 24.

The steam heating coils are utilized-in the apparatus for'carrying out my invention in preference to other common heating means,'-'j

because of the accuracy with which the tem-' perature can be adjusted, particularly if superheated steam is employed therein asiis preferablythe case, 1

The volatile products obtained from the above treatment as actually-fcarriedout, were drawn off through the pipe 23 and collected in a stilland subjected to distillation separately from the undecomposed residues remaining in said digester, at atmospheric pressure and" upon fractional distillation gaveresults'substantially as follows: Up to 100 0., about 5% distillate; between 100 C. and 150 C;, about 10% to 20% distillate;

between. 150 C. and 200 C., about 10% to 20% distillate; between 200 C. and 250 C.,

about 20% to 30% distillate; between 250 C. and 300 0., about 10% distillate.

, While the first "fraction doubtless con tained some volatile paraffin C H the higher distillates were mixtures of some paraflins, some benzene's G H ,:&c. and considerable naphthenes or cyclic or closed -rii1g parafiins, such for example as polyniethylenes, C H and their homologues.

7 The materials which had .been previously 1 :non-volatile below-300 C.', a er treatment uniformly yielded from 65 o to 75% of tieaaao volatile matters at temperatures varying.

pose exactly as though it had not been previously treated, as decomposition takes place at. the appropriate equilibrium and long before all the residue is transformed.

in Fig. 2 the curve shown illustrates the" process when operating up to 300 C. and

the pressures ranging from 30 pounds up to 160 pounds, and in fact experiments show,

that when operating even up to 400 pounds,

the decomposition, recomposition and polymerization, other things being equal, is directly dependent upon the increase of pressure, and that the radical transformation into many new compounds having new molecular arrangements,- does not begin much below five or six atmospheres independent of the temperature. On the other hand, the said experiments indicate that V at pressures ranging from 20 to 30 atmospheres the formation of new compounds --take s place with great rapidity. In all cases the volatile products of decomposition increase with more pressure at temperatures from 200 to. 300 C. This indicates .it is not merely the high temperature, but rather moderate temperature and high pressure that govern the decomposition and determine the result. 7

As a specific example: lVhen operating with heavy, waxy, tarry or pitchy materials. such as Florence, Boulder, WVyoming,

California and Louisiana pitches. at

. temperatures-ranging from 200to 325 C.

and underf'pressures of from 60 to 90 pounds, but a relatively sniall percentage approximating from 25% to 35% of volatile products were obtained. \Vith temperatures from 200up to 325 C. and pressures ranging from 100 to 150 pounds to the square inch, a large percentage of the originally non-volatile material treated was transformed into volatile compounds, the percentage ranging from 50% to 75% of the original. At pressures ranging from 150 pounds up to 300 and 400 pounds per square ingh, and'at temperatures of from 200 to'325. C., from 75% to 90% of the materials were converted into volatile products. These products were in all cases subjected to distillation, at or below atmos- 4:5 a and in the absence, of a foreign compressed menses pheric pressure, separately from the digesting operation. Thus if one starts with a mixture consisting, for example, of parafin of the 0,, El series itis obvious that if it is attempted to split up the said mixture,

into lighter molecules'of the same series'that there will, be enough hydrogen to satisfy but a part of the possible new molecules that maybe formed. The result will be the formation of compounds as C ll 'or even. 0,,H,,,..,, C H C H & c. Now these unsaturated, so to speak, possible compounds, might include the true unsaturated derivatives of the ethylene and acetylene series, although normally this is rarely the case, or of the benzene, toluene, naphthalene, anthracene, etc.,' groups which occasionally happens to be the case, or of the poly-methylene series, the naphthenes as di-, tri-, tetra, penta-, hexa-methylenes, &c., and their derivatives, as is often and usually the case. I

Throughout theclaims the term hydroaromatic as used, includes the cyclic and hydrobenzenes, including naphthenes and the 'poly-mcthylenes; the hydrobenzenes referred to being such compounds as C l-LE CGHGHQ- an& c s s- The positive addition of catalytic materials, as originally described in this appli-. cation, to the materials treated, is not.

- claimed, as such, in this application, but is visional application. 7

s5 -mation' by decomposition, recomposition J what I claim is:

specifically reserved for a co-pendingdl- It is evident as herein described that the requisite pressure for efiech'ng the transferand polymerization of the residues treated into the desired volatile hydrocarbon compounds, is created by and is directly dependent upon the temperature which is employed in the operation. Moreover, in view of the fact that the digester is sealed immediately after the introduction of the residues to be treated, it is evident that this pressure is created wholly without the introduction,

gaseous medium. 7

Having thus described my invention,

1 The process of treating petroleum residues of the parafiin series to increase the yield of volatile compounds above that nor-- mally obtainable therefrom, which consists in digesting the samein a confined space under a pressure in excess of four atmos-' pheres and not exceeding 400 pounds per square inch, said pressure being principally autogenous, and at a temperatureinexcess of 200 C., for a time sufliciently long to induce transformation of the major portion of said materials treated into more volatile products, said temperature being below that point at which suficient carbonization occurs to substantially interfere with such transformation, and said digesting being conducted with the treated materials being continually subjected to the pressure throughout the said digesting period of the evolved volatilized compounds undiluted by added aqueous vapors.

2. The process of treating petroleum residues of the parafin series to increase the yield of volatile compounds above that normally obtainable therefrom, which consists in digesting the same ina confined space under a 'pressure in excess of eight atmospheres and not exceeding 400 pounds per square inch, said pressure being principally autogenous and at a'temperature in excess of 200 for a time ciently long to induce transformation of the major portion of said materials treated into more volatile products, said temperature being below that point at which suficient carbonization occurs to substantially interfere with such transformation, and said digg being conducted with the treated materials being continually subjected to the pressure throughout the said digesting period of the evolved volatilized compounds added aqueous vapors. a

3.. 'lhe process of treating petroleum residues of the parafin series to increase the yield of volatile compounds above that normally obtainable therefrom, which consists undiluted byin digesting the same ina confined space continually subjected to the pressure throughout the said digesting period of the evolved volatilized compounds undilutedhy' added aqueous vapors and then relievin said pressure and separating the evolve volatilized compounds from the non-volatilized compounds.

Signed at New York, in the county of New .York and State of New York, this twenty-sixth day of February, A. l). 1907.

LES S.

Witnesses:

W. H. SWENARTON, JAs. H. Gnrrrm.

conducted with the treated materialsbeing 

